In the words of Mr Bink...
Update: Microsoft changed the article and removed the sp7 part
Windows NT 4.0 Service Pack 7 (SP7), Originally scheduled for to release third quarter of 2001 was canceled on July 2001.
But now that MS extended support till end of 2004, maybe MS reconsiders? Think of the relief the MS helpdesks will get if NT4 servers gets more stable and the relief of server admins not having to install loads of fixes. Remember NT4 SP6a was released released November 30, 1999 few weeks before win2k RTM"ed. Win2k"s sp4 is in the making.
Last time I checked the ftp://hotfix.microsoft.com server there were 500+ post sp6 fixes for NT4, unfortunately MS closed this server. Also I heard that SP7 is installed on OEM servers with NT4 preinstalled, have no proof yet though. And today I bounced on this NT4 KB article and it says: The information in this article applies to: Microsoft Windows NT Server 4.0 SP7
Also the articles keywords contain kbWinNT400SP7fix, this article is the first containing this keyword.